Primary market research : carrying out the market research first hand.
E.g. focus groups, surveys, questionnaires, customer feedback, etc
Benefits: reliable, up-to-date and tailored to your business
Drawbacks: expensive and time-consuming
Secondary market research : analysing information which already exists usually via the internet.
E.g. competitor data, reviews, census, reports, government data , etc
Benefits: easy to find, usually cheaper and less time-consuming
Drawbacks: may be outdated and not specific to your business